Connectivity Analysis of Hippocampus in Alzheimer's Brain Using Probabilistic Tractography

In recent years diffusion tensor imaging (DTI) has received increasing attention from several studies of Alzheimer's disease (AD) since it can reveal the microscopic tissue structure of brain white matter. In Alzheimer's brain both brain regions and inter-regional communications through the white matter are often hampered. In this study, we investigated the white matter tracts in the time series of the three dimensional DTI data obtained from 12 patients with AD and 24 normal control subjects. The probabilistic tractography revealed that the fiber paths of AD patients from the hippocampus toward other brain regions are more scattered and dispersed with less neurotransmitters than those of normal control subjects. Similar patterns were observed in the fiber paths in the reverse directions (i.e., the fiber paths from other brain regions toward the hippocampus). The analysis results can help diagnose AD or predict the prognosis of patients with mild AD.